Barbecued Chicken Casserole

• 4 lb (1.8 kg) oven-ready chicken, jointed
• 2 oz (50

Trim the chicken pieces. Melt the butter in a frying pan over low heat. When hot and foaming, add the chicken pieces and fry for 10 minutes, turning occasionally, until brown all over. Meanwhile, peel and slice the orange. Peel and finely chop the onion for the sauce. Heat the oil in a saucepan over low heat, add the onion and fry gently for 5 minutes to soften but not brown. Transfer the chick